1. Field of the Invention
The instant disclosure relates to an antitumor drug; in particular, to a pH-responsive nanoparticle which can strongly penetrate into tumor tissues.
2. Description of Related Art
The current drugs for curing cancers have significant side effects such as dizziness, hair loss, and skin aging. Hence, researchers have proposed a concept of target therapy. Specifically, target drugs are used to accumulate in tumor tissues through the blood circulation to inhibit the growth of tumor cells. Such called drug controlled release technology has been paid attention to by the medical profession. However, the target drugs existing on the market have many shortcomings that have to be improved. Therefore, the researchers have expended effort to solve the problem of how to decrease the side effects, increase the drug wrapped quantity, and accurately release the drug at the tumor region.
In recent years, polymer micelles have been widely used in medical profession, each of the polymer micelles is composed of amphiphilic polymer chains, wherein one end has hydrophilic chains and the other end has lipophilic chains. The lipophilic chains of the amphiphilic polymer chains would be combined to form a core hydrophobic region in the aqueous phase through the van der Waals force. The core hydrophobic region can be a reservoir for storing lipophilic drugs, and hydrophilic chains are located at the external part of the hydrophobic core to enhance the structural stability of the polymer micelle in the aqueous phase. However, in the highly diluted blood circulation system, the developed polymer micelle still has inferior structural stability and poor accumulation ability for tumor tissues. Thus, the researcher would like to equip a nanocarrier with superior structural stability and effective accumulation ability at the tumor region for the improved delivery of antitumor drugs.